We always had a strong differentiation between FieldBridge(s) included in Hibernate Search, and custom (application provided) FieldBridges. From this release the discovery of built-in bridges uses the Service Loader pattern, so that we can move some bridge implementations to optional modules, and also eventually provide support for the new date/time types defined in Java8 but also by Joda Time, and potentially your own custom types but this will need some further refinement work.